1. Field of the Invention
The present invention generally relates to mufflers for two-stroke internal combustion engines and, more particularly, to such mufflers which incorporate catalyzers to treat the exhaust gases from the engine.
2. Description of the Related Art
The invention is primarily related to small engines of the type used, for example, in portable power-driven tools, such as chain saws. In mufflers provided with a catalyzer element or catalyst, in general, and in mufflers for small engines, in particular, it is preferable that the catalyst begin its full operation as soon as possible after starting of the engine in order to reduce the discharge of impure gases to the largest possible extent. In order to operate properly, the catalyst must have the right temperature and it is important, therefore, that the catalyst be heated as rapidly as possible after starting of the engine.
The catalyst mufflers known in the art do not rapidly heat the catalyzer element, and therefore, do not effectively treat exhaust gases following starting of the engine. Therefore, there exists a need in the art for a catalyzer muffler which rapidly heats the catalyzer element so that the catalyzer can begin effective treatment of the exhaust gases soon after the engine is started.